Tsonga, with nothing to lose now, is swinging freely, firing from corner to corner. 0-15. A mis-hit approach from Federer but he survives at the net, 15-all. Tsonga lets rip, 15-30. Unreturned Federer serve, 30-all. Federer threads a backhand down the line, 40-30. Match point No5. But this time it's on Federer's racket. Tsonga puffs out his cheeks but can do little with the return, giving Federer the initiative, as he charges forward, before finishing things off at the net. The pair embrace warmly. A stunning, explosive match from both players, but it's Federer who survives after three hours and 34 minutes. Now he has the small matter of a semi-final against Andy Murray on Friday (his 33rd grand slam semi). Can't wait. Thanks for reading/emailing etc. Bye.

Tsonga's level has dropped. Two unforced errors bring up two match points, 15-40. Tsonga mutters, but then it's Federer's turn to stutter, 30-40. A big serve down the middle, deuce. That was some second serve on match point. A game of cat and mouse on the next point, both spin and slide around the court, Federer emerges victorious. Match point No3. And what a point! Tsonga, already at the net himself, draws Federer in, Tsonga then somehow controls his forehand volley. Deuce. Advantage Tsonga. Deuce. Advantage Tsonga. Deuce. Advantage Federer, match point No4. Federer nets! Deuce. Advantage Tsonga. Game Tsonga. He's not done yet.

From 15-all, Tsonga goes for a drop shot, which doesn't come off. Probably not the right choice of shot there, a sign his focus – so strong for three and a half hours – is now waning. No such problem for Federer. He's in the zone. 30-15, 40-15, game, rounded off with a delightful forehand volley. "Am I alone in thinking that the arty shot of Roger looks a wee bit like a view out of a pair of nostrils?" muses Michael Hunt.

0-15. Federer now has a stranglehold; he's won 12 of the last 15 points. Sensing the kill, he pounces to make it 0-30. 15-30. A huge slice of luck for Federer on the next point, his backhand slice clips the net, before trickling over and landing on the line. Tsonga can't get there in time. 15-40, two break points to surely settle this match. Tsonga is there for the taking, Federer sends Tsonga one way, then goes the other but somehow misses with the drive volley! 30-40. The match was on his racket there. Tsonga makes the most of his reprieve, getting to deuce, before walloping a forehand down the line. Advantage Tsonga. Game Tsonga! Federer will hope that miss doesn't come back to haunt him.

The last two times Federer has broken, Tsonga has broken straight back. But not this time. Federer gets to 40-15 by plucking a smash out of the air, is briefly inconvenienced as an attempt to serve and volley backfires, but then it's Federer's turn to jog back to his chair as he holds to 30. Surely this is the end game for Tsonga if he doesn't hold now. A crucial game coming up.

A chance for Federer at 0-30. Tsonga scrambles back to 15-30, but then sends a loose backhand long, 15-40. What he'd do for a first serve now. He gets it, but Federer stays with him, and again the backhand breaks down! Federer fist pumps, Mrs Federer nods appreciatively.

This time his answer is a 212kph serve, one of his fastest of the night. He throws in another ace too to make it 17 for the match. Make that 18. Both are serving so well, this is so tough to call. These two have duked it out over five sets once before, Tsonga coming from two sets to love down to beat Federer in the 2011 Wimbledon quarter-finals. Federer will be desperate to settle the score.

Tsonga finds himself in a bit of bother at 15-30, but then makes the most unlikely pass. Federer glares at Tsonga as if to say "How dare you do that to me". Tsonga refuses to be intimidated, the pair slug it out from the baseline on the next point, and Federer blinks first, 40-30, set point. And Tsonga settles things with an ace out wide! We're into a fifth set. Andy Murray has got his wish.

A crowd-pleasing rally on the third point, both go at each other and back at each other, before Tsonga eventually dumps a volley into the net. 30-15. Tsonga lets rips with a ridiculous backhand cross-court winner. 30-all. He then throws missile after missile at Federer at the net. Federer can't withstand the barrage, 30-40. And Tsonga takes the break with a delightful backhand volley! This is Jekyll and Hyde from Tsonga, who will now serve to take this into a final set.

But then Tsonga immediately finds himself in a spot of bother. 15-40. A strong first serve staves off the first, but he succumbs on the second. Tsonga will be kicking himself, that was sloppy, after all of his hard work they're back on serve. And Federer didn't have to do too much to restore parity.

"Hey just wondering how many aces Tsonga has slammed today?" asks Peter McCoy. "Missing what sounds like a brilliant game, but hey people need plastering doing." Selfless Peter. Though how about a sneaky tea break? I make it 13 aces for the match so far. Back on Federer's serve, meanwhile, Tsonga pushes and probes his way to deuce, but he doesn't quite have the flexibility on the next point to prevail. Advantage Federer. Deuce. Advantage Tsonga. That's 50 winners for the Frenchman now, compared to Federer's 38. Remarkable over two hours and 40 minutes of play. Tsonga is throwing absolutely everything at Federer, he's pushing, pushing and pushing. He breaks!

This is high-quality shot-making from both players. Ominous for Murray in the semi-finals? Perhaps, though it's hard to gauge exactly where Murray's game is at considering the way the draw has opened up for him. Tsonga holds to 15, the game reaching a brutal denouement with a punishing rally, which eventually ends when Federer drives a backhand into the net.

This is so focused and mature from Tsonga. There's plenty of showmanship from him while the points are going on, but very little afterwards. Gone are the celebratory pumps and jumps of a few years ago, he'll save that for if he wins. 15-40, two break points to Tsonga. Federer wrong-foots Tsonga on the first, hitting deep to Tsonga's forehand wing and then going back behind him as Tsonga was trying to scramble back to the centre. Federer repeats the trick on the second. Deuce. Advantage Federer. Game Federer. Now it's Federer's turn to get himself out of a service predicament.

Wow. Strike after strike after strike from Federer gives him three break points, 0-40. He misses the first after a bit of tête-à-tête at the net (I'm getting into this French speaking now), he misses the second when a backhand flops into the net, and there's nothing he can do about the third because Tsonga slams an ace down the T. A fourth break point comes and goes as Tsonga swats away the danger with a venomous forehand, the power he generated was incredible considering his position behind the baseline. Deuce. Advantage Tsonga. Game Tsonga. A huge hold.

The standard is being cranked up as every set goes by. Both players are hitting winner after winner right now. Federer holds to 15, Tsonga has a little monologue in French, though I'm afraid my linguistic skills are such that I can't tell you what he said. Je suis désolé.

Credit to Tsonga. After the disappointment of being denied in that third set, he comes straight back at Federer, with all his energy, athleticism and power. The pick of the points sees him hurtle into the net to pull off a bit of a trick shot. Lovely stuff. He holds to love. Tsonga isn't willing the concede this one yet.

"LET'S GO TSONGA, LET'S GO," scream the Frenchman's fanclub. Even some of the Swiss are getting a bit rowdy too. An unbelievable return from Federer, backed up with a viciously spun forehand winner, gets him to 4-3. Then 5-3. Some wonderful play. Tsonga then commits to a second-serve return, before putting away a tricky volley with aplomb. 5-4. 6-4. Federer has two set points, and he takes the set at the first time of asking when Tsonga this time fluffs his lines at the net, though admittedly under much pressure from Federer. Superb from the Swiss, who found his best form when it mattered. The crowd stand to salute the maestro.

Two comfortable service holds make it 1-all. But then Tsonga, a little flat footed, becomes a sitting target at the net. 2-1 Federer. A big gasp from the Melbourne patrons on the next point, Federer opts to go for a drive volley rather than let the ball bounce, and he flunks it into the net. 2-all. 3-2 to Federer courtesy of an inside-out cross-court missile. Make that 3-all at the changeover ...

Tsonga, serving with the new balls, sends a searing forehand deep to Federer's left side. But Federer grapples back the initiative, 15-all, then 15-30, with a quite ridiculous return. Mats Wilander calls it as the shot of the tournament. Tsonga reverts to his go-to shot, the inside out forehand, 30-all. Federer goes long after a lengthy exchange, 40-30. Federer challenges, perhaps only to buy himself a few seconds breathing space, it was always out. Tsonga holds. We're into another breaker.

But Tsonga isn't just about raw power. A clever backhand slice teases the error from Federer, 0-15. Federer, for all the world, looks like he'll bury a forehand on the next point, but it's an ugly, ugly error. 0-30. But the beast turns back into the beauty on the next, as Federer arrows a darting backhand down the line. 15-30. 30-all. 40-30. Game. Four points on the spin and Tsonga must once again hold serve to stay in this set. The crowd rises.

A straightforward hold for Federer, to 15, the highlight a lovely backhand volley on the stretch which gets him to 40-15. With all the baseline tennis these days, we should admire the net prowess of these two. This is superb stuff.

Perhaps the hardest two-handed backhand Tsonga has hit comes back at him with interest, 30-0. Make that 40-0 when Federer fires down an ace. Make that game as Federer smashes down an overhead, which crashes into the service box. "If it carries on like this, Andy Murray might just get his wish of a five-hour match," emails Peter Foster. "Sounds as though Federer is not fully on his game yet, but Tsonga can do that to anyone with his power and energy." Talking of Murray, Peter, we know his semi-final will be the night match on Rod Laver on Friday evening Melbourne time, so Friday morning UK time.

Tsonga again chips, chips, chips away at the Federer backhand, a tactic which is serving the Frenchman well. 30-15. Again Tsonga strikes at Federer's backhand wing, Federer, stretching every sinew, nets. 40-15. The pair duke it out from the middle of the court on the next point, before Tsonga mixes things up with a cross-court swat, leaving Federer stranded.

A game which ebbs and flows, ebbs and flows. From 15-all, Federer has Tsonga on the back foot with a probing cross-court forehand, and he then charges into the net to settle matters, 15-30. But that soon becomes 30-all, which soon becomes 40-30, courtesy of a brave second serve from Tsonga that jammed right into Federer's body. Federer forges his way to deuce, before Tsonga steps round his backhand, picking Federer off with a brutal forehand down the line. Federer barely moves. Advantage Tsonga. Deuce. Advantage Tsonga. Deuce. Advantage Federer. Deuce – with a cross-court scorcher from Tsonga. And Tsonga comes through to hold, to prevent a third successive break of serve.

At 30-all, a big decision by Tsonga. The Frenchman thinks Federer's shot was out, the linesman didn't call it, neither did the umpire. Tsonga stops playing and raises his hand to Hawk-Eye. If he's wrong, he'll concede the point. But look, he's right! Break point. And Tsonga breaks back.

Tsonga looks to have got himself out of a bit of a hole when he rounds off the rally of the match with a forehand winner, 30-all. But a slam-dunked smash from Federer makes it 30-40, break point. His first break chance for a long while. Will he capitalise? Yes he does, as Tsonga can only slap a backhand volley into the net. Tsonga looks mad with himself, Federer looks like Federer usually does whether he's winning or losing, fairly serene. Well played by the world No2, and he'll now serve with the new balls at the perfect time.

I'm not entirely sure what to make of this match so far. There have been some fantastic points, but some fairly average ones as well. Especially from Federer towards the end of that second set. Federer regroups with a quicker than quick service game, holding to 15. A wicked kick on his second serve leaving Tsonga stretching, spinning and sliding on the final point.

Tsonga gets off to the best possible start with a 135mph ace, his fastest of the day. Federer has a chance to pass on the next point, but goes about 1cm long. That was a chance. 30-0. Federer then slaps the net with a mistimed backhand, 40-0. He's all at sea right now. Three set points. Tsonga misses with a wild and wayward forehand on the first, but makes no mistake on the second, firing down another service Exocet. Game on.

A wonderful running pass from Tsonga gets the crowd going, 15-all. Federer then throws in another unforced error, his 21st of the match, 15-30. But Federer chips and chops, leaving Tsonga bamboozled, 30-all, before a nerveless drive volley makes it 40-30. Tsonga's return goes well wide, game. Tsonga must serve this one out.

So can Tsonga hold his nerve? The answer seems to be yes. Some strong, solid hitting from the Frenchman gets him to 40-0. Nothing fancy, mind. It doesn't need to be. Federer's lost his range, he's going for his shots just a little bit too much, and he's in danger of losing this second set.

A collective gasp at 15-all as Federer's forehand clips the top of the net. It looks like it might trickle over, but after what feels like an age the ball slumps into the net. A glimmer for Tsonga, 15-30. And the glimmer quickly becomes a break point at 30-40. Suddenly this set springs into life. The pair trade baseline blow after baseline blow, and Federer ends up flooring himself by hoiking a forehand into the tramlines! Federer held serve 57 successive times coming into this match, he's now been broken twice.

You already know how this one goes, right? A sixth ace from Tsonga, 15-0. Unreturned serve, 30-0. Unreturned serve, 40-0. Netted Federer backhand, game. Tsonga's in his serving groove, but so is Federer. Who will blink first?

A little more subtlety in this game, including a delightful touch volley from Federer to make it 15-all, but the majority of these points are so brief. This set has been dominated by serve, there are few nuances here. Bish, bash, bosh. From 15-all, Federer rattles off the next three points.

A fourth ace of the day brings up game point for Federer, 40-15. He's found his serving range now. Tsonga provides some brief resistance as he net charges once again, 40-30. But Federer averts the danger.

Federer, with the wind in his sails, holds to love, the highlight a great serve-and-volley point to get to 40-0. He then settles the game by coming in to dispatch an overhead. Tsonga must find a way of keeping pace with Federer now, who's looking calm, relaxed and in the zone. That's what sneaking the first set will do to you.

... and a big slice of luck gets Federer to 5-2. A 207kph serve out wide from Tsonga, wow. That's three aces apiece now. 5-3. Federer looks to have the better of Tsonga on the next point, pushing and pulling and probing, but Tsonga somehow darts a forehand passing winner down the line. 5-4. Federer will still have two serves to settle this set, though. And that's all he needs. By far Federer's most testing set of the tournament so far, in which he was broken for the first time, but he's edged through. Tsonga will be disappointed, the way he came back at Federer in that set he will feel it was there for the taking.

Tsonga thinks he's opened the breaker with an ace, but the umpire Jake Garner overrules, and Hawk-Eye confirms it was out. Federer goes on to get the mini-break and then consolidates it to go 2-0 ahead. The pair duke it out from the back of the court, but Tsonga, under little pressure, loses his footing and his forehand drops into the net. 3-0. Make that 3-2 after two explosive points from the Tsonga. You've got to love his showmanship. Federer then decides to get in on a bit of net-rushing action himself, 4-2. The pair change ends ...

Federer is starting to find a little more rhythm on his first serve now, as his percentage nudges over 50 for the first time. 15-all. A whipped Federer inside-out forehand leaves Tsonga skidding and sliding, 30-15. Another vicious inside-out forehand, another error from Tsonga, 40-15. And Federer then rounds things off with an ace out wide. A tie-break it is, then.

A game of cat and mouse on the second point, Tsonga comes into the net before drawing in Federer too and emerging the victor. 30-0. Tsonga then puffs out his cheeks before firing a ferocious forehand down the line. 40-0. Such firepower from the Frenchman. And he then unleashes a bit more to take the game. "I am very impressesd with jo-willy game plan so far can he do this for the the whole match?" asks Brad Gilbert on Twitter.

The commentators on Eurosport are debating how much of a factor Federer's lack of a warm-up event could be now he's at the business end of this tournament. His last competition was at the O2 back in November. If he hadn't met some tough opponents already in Bernard Tomic and Milos Raonic, you'd say maybe yes, it could harm him. But he's already been tested. And there's no doubt he's being tested here. Plenty of oooohs and aaaahs at 30-all, as Federer somehow retrieves a smash, leaving Tsonga bamboozled. 30-40. Federer sees a gap down the line, unwinds on the forehand, but nets. Deuce. And Tsonga then squeaks through. Federer must serve to stay in the first set.

Federer, having been broken, decides to change his racket. There's probably not much to read into that, though. He's most likely preparing himself for the new balls which will be coming up in a game's time. What looks like a routine hold for Tsonga at 40-0 suddenly becomes a bit more complicated as Federer gets to 40-30, with the longest rally of the match so far, 17 shots. But Tsonga then slams down a smash to hold to 30. He's ahead for the first time and is cranking up the pressure. How will Federer respond?

A few careless points from Federer. He concedes the first with a volley he probably didn't need to make, and the second with a miscued backhand. He glares at a camera which was apparently distracting him. See, it wasn't his fault. He regroups, as 0-30 quickly becomes 30-all which quickly becomes 40-30. A wonderful point then ensues, which Tsonga finishes off by coming into the net and dispatching a backhand stop volley. Great precision, the ball was coming at Tsonga fairly fast. Deuce. And then Tsonga absolutely rips a winning forehand return to give himself break point. And this time he takes it. Fantastic hitting from the Frenchman.

The pair trade cross-court backhand after cross-court backhand, Tsonga prevails, 30-0. He certainly seems to be picking on Federer's backhand side early on. From 40-0, Federer's best shot of the match so far, as he pings a forehand winner down the line on the run and on the stretch. 40-15. But that's as far as Federer gets as Tsonga holds to 15.

Tsonga is already so far behind the baseline, almost on a piece of string, being dragged from side to side and back and forth by Federer. But then he cuts himself free, and at 30-all, Federer completely shanks a backhand, which ends up in row Z. 30-40, break point. Federer dismisses the danger with a nonchalant swat. It looks like Tsonga might have twinged something in his back there, he's grimacing and clutching it. Deuce. Advantage Tsonga. Deuce. Advantage Federer. Game Federer.

A game of fluctuations. Tsonga steams 40-0 ahead. Federer finds a way back to 40-30. But Federer then goes for broke on the return, and it skips just long. A crucial hold for Tsonga, even so early in this match.

Move on ladies and gents, there's little to see here. 15-0, 30-0, 40-0, game. These two have history, by the way. Federer surely hasn't forgotten his five-set defeat against Tsonga in the 2011 Wimbledon quarter-finals. It was the first time Federer had lost a grand slam match from two sets up. But the four-times champion has accounted for Tsonga in eight of their 11 past meetings, including a straight-sets defeat in the Australian Open quarter-finals three years ago.

Tsonga steps up to serve first in front of a packed Rod Laver Arena. His first serve goes well long, his second is slightly soft, and Federer is able to take command in the point before Tsonga goes wide. Tsonga restores early parity with a lovely backhand volley, expect plenty of forays to the net from the Frenchman today. 15-all. But then Federer charges ahead with two lightning points to bring up two early break chances, 15-40. Tsonga saves the first with a 130mph serve bomb, but is unable to fend off the second. The Frenchman bravely opts to serve-volley, but the volley sails into the tramlines. Game and break Federer.

The players are winding their way through the corridors and on to court, Tsonga about 10 steps ahead, not wanting to make eye contact with Federer. And here's Clive Darwell, who reckons the bookies have got it right: "The bookmakers along with other sports fans know that early form counts for very little in major tournaments – and Fed's done it before, started well and then come unstuck especially in recent years." True. It's the business end that matters. And encouragingly for Murray, he did step it up a notch against Chardy earlier.

Preamble

Morning all.Roger Federer could be forgiven for wondering what he needs to do to shake up the odds. The second seed started this Australian Open in the slightly skewed position of being the third favourite, and it’s a status he still has with the bookmakers despite his imperious form. While Novak Djokovic has already been taken to the brink and Andy Murray has taken a while to find his A game, Federer’s been in sublime touch from the off. He’s won all four of his matches in straight sets, hasn’t dropped his serve and dealt with the dangermen Bernard Tomic and Milos Raonic with frightening efficiency. The game’s greatest will perhaps feel he deserves more respect.

The question of R-E-S-P-E-C-T has been on Jo Wilfried-Tsonga’s mind too. "I've got a lot of respect for Federer outside of the court,” the seventh seed said ahead of their quarter-final, “but on the court, I have to – how you say – unrespect him? Because if you respect him too much, then for sure you lose. We have a good relationship in the locker room, but it's different on the court. On the court, I will try to beat him and I'm sure it's going to be the same thing for him."

This match-up is the statesman versus the showman, the 17-times grand slam champion against the explosive, unpredictable and flashy Frenchman. A few Melbourne loyalties may be divided; Tsonga is held in great affection in Australia after his breakthrough run to the final five years ago, while Federer is, well, Federer, revered wherever he goes. At least he’s got the crowd’s respect.